sound/drivers/aloop.c

   1 /*
   2  *  Loopback soundcard
   3  *
   4  *  Original code:
   5  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
   6  *
   7  *  More accurate positioning and full-duplex support:
   8  *  Copyright (c) Ahmet İnan <ainan at mathematik.uni-freiburg.de>
   9  *
  10  *  Major (almost complete) rewrite:
  11  *  Copyright (c) by Takashi Iwai <tiwai@suse.de>
  12  *
  13  *  A next major update in 2010 (separate timers for playback and capture):
  14  *  Copyright (c) Jaroslav Kysela <perex@perex.cz>
  15  *
  16  *   This program is free software; you can redistribute it and/or modify
  17  *   it under the terms of the GNU General Public License as published by
  18  *   the Free Software Foundation; either version 2 of the License, or
  19  *   (at your option) any later version.
  20  *
  21  *   This program is distributed in the hope that it will be useful,
  22  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  23  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  24  *   GNU General Public License for more details.
  25  *
  26  *   You should have received a copy of the GNU General Public License
  27  *   along with this program; if not, write to the Free Software
  28  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  29  *
  30  */
  31
  32 #include <linux/init.h>
  33 #include <linux/jiffies.h>
  34 #include <linux/slab.h>
  35 #include <linux/time.h>
  36 #include <linux/wait.h>
  37 #include <linux/moduleparam.h>
  38 #include <linux/platform_device.h>
  39 #include <sound/core.h>
  40 #include <sound/control.h>
  41 #include <sound/pcm.h>
  42 #include <sound/info.h>
  43 #include <sound/initval.h>
  44
  45 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
  46 MODULE_DESCRIPTION("A loopback soundcard");
  47 MODULE_LICENSE("GPL");
  48 MODULE_SUPPORTED_DEVICE("{{ALSA,Loopback soundcard}}");
  49
  50 #define MAX_PCM_SUBSTREAMS      8
  51
  52 static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;      /* Index 0-MAX */
  53 static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;       /* ID for this card */
  54 static int enable[SNDRV_CARDS] = {1, [1 ... (SNDRV_CARDS - 1)] = 0};
  55 static int pcm_substreams[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 8};
  56 static int pcm_notify[SNDRV_CARDS];
  57
  58 module_param_array(index, int, NULL, 0444);
  59 MODULE_PARM_DESC(index, "Index value for loopback soundcard.");
  60 module_param_array(id, charp, NULL, 0444);
  61 MODULE_PARM_DESC(id, "ID string for loopback soundcard.");
  62 module_param_array(enable, bool, NULL, 0444);
  63 MODULE_PARM_DESC(enable, "Enable this loopback soundcard.");
  64 module_param_array(pcm_substreams, int, NULL, 0444);
  65 MODULE_PARM_DESC(pcm_substreams, "PCM substreams # (1-8) for loopback driver.");
  66 module_param_array(pcm_notify, int, NULL, 0444);
  67 MODULE_PARM_DESC(pcm_notify, "Break capture when PCM format/rate/channels changes.");
  68
  69 #define NO_PITCH 100000
  70
  71 struct loopback_pcm;
  72
  73 struct loopback_cable {
  74         spinlock_t lock;
  75         struct loopback_pcm *streams[2];
  76         struct snd_pcm_hardware hw;
  77         /* flags */
  78         unsigned int valid;
  79         unsigned int running;
  80 };
  81
  82 struct loopback_setup {
  83         unsigned int notify: 1;
  84         unsigned int rate_shift;
  85         unsigned int format;
  86         unsigned int rate;
  87         unsigned int channels;
  88         struct snd_ctl_elem_id active_id;
  89         struct snd_ctl_elem_id format_id;
  90         struct snd_ctl_elem_id rate_id;
  91         struct snd_ctl_elem_id channels_id;
  92 };
  93
  94 struct loopback {
  95         struct snd_card *card;
  96         struct mutex cable_lock;
  97         struct loopback_cable *cables[MAX_PCM_SUBSTREAMS][2];
  98         struct snd_pcm *pcm[2];
  99         struct loopback_setup setup[MAX_PCM_SUBSTREAMS][2];
 100 };
 101
 102 struct loopback_pcm {
 103         struct loopback *loopback;
 104         struct snd_pcm_substream *substream;
 105         struct loopback_cable *cable;
 106         unsigned int pcm_buffer_size;
 107         unsigned int buf_pos;   /* position in buffer */
 108         unsigned int silent_size;
 109         /* PCM parameters */
 110         unsigned int pcm_period_size;
 111         unsigned int pcm_bps;           /* bytes per second */
 112         unsigned int pcm_salign;        /* bytes per sample * channels */
 113         unsigned int pcm_rate_shift;    /* rate shift value */
 114         /* flags */
 115         unsigned int period_update_pending :1;
 116         /* timer stuff */
 117         unsigned int irq_pos;           /* fractional IRQ position */
 118         unsigned int period_size_frac;
 119         unsigned long last_jiffies;
 120         struct timer_list timer;
 121 };
 122
 123 static struct platform_device *devices[SNDRV_CARDS];
 124
 125 static inline unsigned int byte_pos(struct loopback_pcm *dpcm, unsigned int x)
 126 {
 127         if (dpcm->pcm_rate_shift == NO_PITCH) {
 128                 x /= HZ;
 129         } else {
 130                 x = div_u64(NO_PITCH * (unsigned long long)x,
 131                             HZ * (unsigned long long)dpcm->pcm_rate_shift);
 132         }
 133         return x - (x % dpcm->pcm_salign);
 134 }
 135
 136 static inline unsigned int frac_pos(struct loopback_pcm *dpcm, unsigned int x)
 137 {
 138         if (dpcm->pcm_rate_shift == NO_PITCH) { /* no pitch */
 139                 return x * HZ;
 140         } else {
 141                 x = div_u64(dpcm->pcm_rate_shift * (unsigned long long)x * HZ,
 142                             NO_PITCH);
 143         }
 144         return x;
 145 }
 146
 147 static inline struct loopback_setup *get_setup(struct loopback_pcm *dpcm)
 148 {
 149         int device = dpcm->substream->pstr->pcm->device;
 150
 151         if (dpcm->substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 152                 device ^= 1;
 153         return &dpcm->loopback->setup[dpcm->substream->number][device];
 154 }
 155
 156 static inline unsigned int get_notify(struct loopback_pcm *dpcm)
 157 {
 158         return get_setup(dpcm)->notify;
 159 }
 160
 161 static inline unsigned int get_rate_shift(struct loopback_pcm *dpcm)
 162 {
 163         return get_setup(dpcm)->rate_shift;
 164 }
 165
 166 static void loopback_timer_start(struct loopback_pcm *dpcm)
 167 {
 168         unsigned long tick;
 169         unsigned int rate_shift = get_rate_shift(dpcm);
 170
 171         if (rate_shift != dpcm->pcm_rate_shift) {
 172                 dpcm->pcm_rate_shift = rate_shift;
 173                 dpcm->period_size_frac = frac_pos(dpcm, dpcm->pcm_period_size);
 174         }
 175         if (dpcm->period_size_frac <= dpcm->irq_pos) {
 176                 dpcm->irq_pos %= dpcm->period_size_frac;
 177                 dpcm->period_update_pending = 1;
 178         }
 179         tick = dpcm->period_size_frac - dpcm->irq_pos;
 180         tick = (tick + dpcm->pcm_bps - 1) / dpcm->pcm_bps;
 181         dpcm->timer.expires = jiffies + tick;
 182         add_timer(&dpcm->timer);
 183 }
 184
 185 static inline void loopback_timer_stop(struct loopback_pcm *dpcm)
 186 {
 187         del_timer(&dpcm->timer);
 188         dpcm->timer.expires = 0;
 189 }
 190
 191 #define CABLE_VALID_PLAYBACK    (1 << SNDRV_PCM_STREAM_PLAYBACK)
 192 #define CABLE_VALID_CAPTURE     (1 << SNDRV_PCM_STREAM_CAPTURE)
 193 #define CABLE_VALID_BOTH        (CABLE_VALID_PLAYBACK|CABLE_VALID_CAPTURE)
 194
 195 static int loopback_check_format(struct loopback_cable *cable, int stream)
 196 {
 197         struct snd_pcm_runtime *runtime, *cruntime;
 198         struct loopback_setup *setup;
 199         struct snd_card *card;
 200         int check;
 201
 202         if (cable->valid != CABLE_VALID_BOTH) {
 203                 if (stream == SNDRV_PCM_STREAM_PLAYBACK)
 204                         goto __notify;
 205                 return 0;
 206         }
 207         runtime = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->
 208                                                         substream->runtime;
 209         cruntime = cable->streams[SNDRV_PCM_STREAM_CAPTURE]->
 210                                                         substream->runtime;
 211         check = runtime->format != cruntime->format ||
 212                 runtime->rate != cruntime->rate ||
 213                 runtime->channels != cruntime->channels;
 214         if (!check)
 215                 return 0;
 216         if (stream == SNDRV_PCM_STREAM_CAPTURE) {
 217                 return -EIO;
 218         } else {
 219                 snd_pcm_stop(cable->streams[SNDRV_PCM_STREAM_CAPTURE]->
 220                                         substream, SNDRV_PCM_STATE_DRAINING);
 221               __notify:
 222                 runtime = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->
 223                                                         substream->runtime;
 224                 setup = get_setup(cable->streams[SNDRV_PCM_STREAM_PLAYBACK]);
 225                 card = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->loopback->card;
 226                 if (setup->format != runtime->format) {
 227                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
 228                                                         &setup->format_id);
 229                         setup->format = runtime->format;
 230                 }
 231                 if (setup->rate != runtime->rate) {
 232                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
 233                                                         &setup->rate_id);
 234                         setup->rate = runtime->rate;
 235                 }
 236                 if (setup->channels != runtime->channels) {
 237                         snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
 238                                                         &setup->channels_id);
 239                         setup->channels = runtime->channels;
 240                 }
 241         }
 242         return 0;
 243 }
 244
 245 static void loopback_active_notify(struct loopback_pcm *dpcm)
 246 {
 247         snd_ctl_notify(dpcm->loopback->card,
 248                        SNDRV_CTL_EVENT_MASK_VALUE,
 249                        &get_setup(dpcm)->active_id);
 250 }
 251
 252 static int loopback_trigger(struct snd_pcm_substream *substream, int cmd)
 253 {
 254         struct snd_pcm_runtime *runtime = substream->runtime;
 255         struct loopback_pcm *dpcm = runtime->private_data;
 256         struct loopback_cable *cable = dpcm->cable;
 257         int err;
 258
 259         switch (cmd) {
 260         case SNDRV_PCM_TRIGGER_START:
 261                 err = loopback_check_format(cable, substream->stream);
 262                 if (err < 0)
 263                         return err;
 264                 dpcm->last_jiffies = jiffies;
 265                 dpcm->pcm_rate_shift = 0;
 266                 loopback_timer_start(dpcm);
 267                 cable->running |= (1 << substream->stream);
 268                 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 269                         loopback_active_notify(dpcm);
 270                 break;
 271         case SNDRV_PCM_TRIGGER_STOP:
 272                 cable->running &= ~(1 << substream->stream);
 273                 loopback_timer_stop(dpcm);
 274                 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 275                         loopback_active_notify(dpcm);
 276                 break;
 277         default:
 278                 return -EINVAL;
 279         }
 280         return 0;
 281 }
 282
 283 static void params_change_substream(struct loopback_pcm *dpcm,
 284                                     struct snd_pcm_runtime *runtime)
 285 {
 286         struct snd_pcm_runtime *dst_runtime;
 287
 288         if (dpcm == NULL || dpcm->substream == NULL)
 289                 return;
 290         dst_runtime = dpcm->substream->runtime;
 291         if (dst_runtime == NULL)
 292                 return;
 293         dst_runtime->hw = dpcm->cable->hw;
 294 }
 295
 296 static void params_change(struct snd_pcm_substream *substream)
 297 {
 298         struct snd_pcm_runtime *runtime = substream->runtime;
 299         struct loopback_pcm *dpcm = runtime->private_data;
 300         struct loopback_cable *cable = dpcm->cable;
 301
 302         cable->hw.formats = (1ULL << runtime->format);
 303         cable->hw.rate_min = runtime->rate;
 304         cable->hw.rate_max = runtime->rate;
 305         cable->hw.channels_min = runtime->channels;
 306         cable->hw.channels_max = runtime->channels;
 307         params_change_substream(cable->streams[SNDRV_PCM_STREAM_PLAYBACK],
 308                                 runtime);
 309         params_change_substream(cable->streams[SNDRV_PCM_STREAM_CAPTURE],
 310                                 runtime);
 311 }
 312
 313 static int loopback_prepare(struct snd_pcm_substream *substream)
 314 {
 315         struct snd_pcm_runtime *runtime = substream->runtime;
 316         struct loopback_pcm *dpcm = runtime->private_data;
 317         struct loopback_cable *cable = dpcm->cable;
 318         int bps, salign;
 319
 320         salign = (snd_pcm_format_width(runtime->format) *
 321                                                 runtime->channels) / 8;
 322         bps = salign * runtime->rate;
 323         if (bps <= 0 || salign <= 0)
 324                 return -EINVAL;
 325
 326         dpcm->buf_pos = 0;
 327         dpcm->pcm_buffer_size = frames_to_bytes(runtime, runtime->buffer_size);
 328         if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
 329                 /* clear capture buffer */
 330                 dpcm->silent_size = dpcm->pcm_buffer_size;
 331                 snd_pcm_format_set_silence(runtime->format, runtime->dma_area,
 332                                            runtime->buffer_size * runtime->channels);
 333         }
 334
 335         dpcm->irq_pos = 0;
 336         dpcm->period_update_pending = 0;
 337         dpcm->pcm_bps = bps;
 338         dpcm->pcm_salign = salign;
 339         dpcm->pcm_period_size = frames_to_bytes(runtime, runtime->period_size);
 340
 341         mutex_lock(&dpcm->loopback->cable_lock);
 342         if (!(cable->valid & ~(1 << substream->stream)) ||
 343             (get_setup(dpcm)->notify &&
 344              substream->stream == SNDRV_PCM_STREAM_PLAYBACK))
 345                 params_change(substream);
 346         cable->valid |= 1 << substream->stream;
 347         mutex_unlock(&dpcm->loopback->cable_lock);
 348
 349         return 0;
 350 }
 351
 352 static void clear_capture_buf(struct loopback_pcm *dpcm, unsigned int bytes)
 353 {
 354         struct snd_pcm_runtime *runtime = dpcm->substream->runtime;
 355         char *dst = runtime->dma_area;
 356         unsigned int dst_off = dpcm->buf_pos;
 357
 358         if (dpcm->silent_size >= dpcm->pcm_buffer_size)
 359                 return;
 360         if (dpcm->silent_size + bytes > dpcm->pcm_buffer_size)
 361                 bytes = dpcm->pcm_buffer_size - dpcm->silent_size;
 362
 363         for (;;) {
 364                 unsigned int size = bytes;
 365                 if (dst_off + size > dpcm->pcm_buffer_size)
 366                         size = dpcm->pcm_buffer_size - dst_off;
 367                 snd_pcm_format_set_silence(runtime->format, dst + dst_off,
 368                                            bytes_to_frames(runtime, size) *
 369                                                 runtime->channels);
 370                 dpcm->silent_size += size;
 371                 bytes -= size;
 372                 if (!bytes)
 373                         break;
 374                 dst_off = 0;
 375         }
 376 }
 377
 378 static void copy_play_buf(struct loopback_pcm *play,
 379                           struct loopback_pcm *capt,
 380                           unsigned int bytes)
 381 {
 382         struct snd_pcm_runtime *runtime = play->substream->runtime;
 383         char *src = runtime->dma_area;
 384         char *dst = capt->substream->runtime->dma_area;
 385         unsigned int src_off = play->buf_pos;
 386         unsigned int dst_off = capt->buf_pos;
 387         unsigned int clear_bytes = 0;
 388
 389         /* check if playback is draining, trim the capture copy size
 390          * when our pointer is at the end of playback ring buffer */
 391         if (runtime->status->state == SNDRV_PCM_STATE_DRAINING &&
 392             snd_pcm_playback_hw_avail(runtime) < runtime->buffer_size) {
 393                 snd_pcm_uframes_t appl_ptr, appl_ptr1, diff;
 394                 appl_ptr = appl_ptr1 = runtime->control->appl_ptr;
 395                 appl_ptr1 -= appl_ptr1 % runtime->buffer_size;
 396                 appl_ptr1 += play->buf_pos / play->pcm_salign;
 397                 if (appl_ptr < appl_ptr1)
 398                         appl_ptr1 -= runtime->buffer_size;
 399                 diff = (appl_ptr - appl_ptr1) * play->pcm_salign;
 400                 if (diff < bytes) {
 401                         clear_bytes = bytes - diff;
 402                         bytes = diff;
 403                 }
 404         }
 405
 406         for (;;) {
 407                 unsigned int size = bytes;
 408                 if (src_off + size > play->pcm_buffer_size)
 409                         size = play->pcm_buffer_size - src_off;
 410                 if (dst_off + size > capt->pcm_buffer_size)
 411                         size = capt->pcm_buffer_size - dst_off;
 412                 memcpy(dst + dst_off, src + src_off, size);
 413                 capt->silent_size = 0;
 414                 bytes -= size;
 415                 if (!bytes)
 416                         break;
 417                 src_off = (src_off + size) % play->pcm_buffer_size;
 418                 dst_off = (dst_off + size) % capt->pcm_buffer_size;
 419         }
 420
 421         if (clear_bytes > 0) {
 422                 clear_capture_buf(capt, clear_bytes);
 423                 capt->silent_size = 0;
 424         }
 425 }
 426
 427 #define BYTEPOS_UPDATE_POSONLY  0
 428 #define BYTEPOS_UPDATE_CLEAR    1
 429 #define BYTEPOS_UPDATE_COPY     2
 430
 431 static void loopback_bytepos_update(struct loopback_pcm *dpcm,
 432                                     unsigned int delta,
 433                                     unsigned int cmd)
 434 {
 435         unsigned int count;
 436         unsigned long last_pos;
 437
 438         last_pos = byte_pos(dpcm, dpcm->irq_pos);
 439         dpcm->irq_pos += delta * dpcm->pcm_bps;
 440         count = byte_pos(dpcm, dpcm->irq_pos) - last_pos;
 441         if (!count)
 442                 return;
 443         if (cmd == BYTEPOS_UPDATE_CLEAR)
 444                 clear_capture_buf(dpcm, count);
 445         else if (cmd == BYTEPOS_UPDATE_COPY)
 446                 copy_play_buf(dpcm->cable->streams[SNDRV_PCM_STREAM_PLAYBACK],
 447                               dpcm->cable->streams[SNDRV_PCM_STREAM_CAPTURE],
 448                               count);
 449         dpcm->buf_pos += count;
 450         dpcm->buf_pos %= dpcm->pcm_buffer_size;
 451         if (dpcm->irq_pos >= dpcm->period_size_frac) {
 452                 dpcm->irq_pos %= dpcm->period_size_frac;
 453                 dpcm->period_update_pending = 1;
 454         }
 455 }
 456
 457 static void loopback_pos_update(struct loopback_cable *cable)
 458 {
 459         struct loopback_pcm *dpcm_play =
 460                         cable->streams[SNDRV_PCM_STREAM_PLAYBACK];
 461         struct loopback_pcm *dpcm_capt =
 462                         cable->streams[SNDRV_PCM_STREAM_CAPTURE];
 463         unsigned long delta_play = 0, delta_capt = 0;
 464
 465         spin_lock(&cable->lock);
 466         if (cable->running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) {
 467                 delta_play = jiffies - dpcm_play->last_jiffies;
 468                 dpcm_play->last_jiffies += delta_play;
 469         }
 470
 471         if (cable->running & (1 << SNDRV_PCM_STREAM_CAPTURE)) {
 472                 delta_capt = jiffies - dpcm_capt->last_jiffies;
 473                 dpcm_capt->last_jiffies += delta_capt;
 474         }
 475
 476         if (delta_play == 0 && delta_capt == 0) {
 477                 spin_unlock(&cable->lock);
 478                 return;
 479         }
 480
 481         if (delta_play > delta_capt) {
 482                 loopback_bytepos_update(dpcm_play, delta_play - delta_capt,
 483                                         BYTEPOS_UPDATE_POSONLY);
 484                 delta_play = delta_capt;
 485         } else if (delta_play < delta_capt) {
 486                 loopback_bytepos_update(dpcm_capt, delta_capt - delta_play,
 487                                         BYTEPOS_UPDATE_CLEAR);
 488                 delta_capt = delta_play;
 489         }
 490
 491         if (delta_play == 0 && delta_capt == 0) {
 492                 spin_unlock(&cable->lock);
 493                 return;
 494         }
 495         /* note delta_capt == delta_play at this moment */
 496         loopback_bytepos_update(dpcm_capt, delta_capt, BYTEPOS_UPDATE_COPY);
 497         loopback_bytepos_update(dpcm_play, delta_play, BYTEPOS_UPDATE_POSONLY);
 498         spin_unlock(&cable->lock);
 499 }
 500
 501 static void loopback_timer_function(unsigned long data)
 502 {
 503         struct loopback_pcm *dpcm = (struct loopback_pcm *)data;
 504         int stream;
 505
 506         loopback_pos_update(dpcm->cable);
 507         stream = dpcm->substream->stream;
 508         if (dpcm->cable->running & (1 << stream))
 509                 loopback_timer_start(dpcm);
 510         if (dpcm->period_update_pending) {
 511                 dpcm->period_update_pending = 0;
 512                 if (dpcm->cable->running & (1 << stream))
 513                         snd_pcm_period_elapsed(dpcm->substream);
 514         }
 515 }
 516
 517 static snd_pcm_uframes_t loopback_pointer(struct snd_pcm_substream *substream)
 518 {
 519         struct snd_pcm_runtime *runtime = substream->runtime;
 520         struct loopback_pcm *dpcm = runtime->private_data;
 521
 522         loopback_pos_update(dpcm->cable);
 523         return bytes_to_frames(runtime, dpcm->buf_pos);
 524 }
 525
 526 static struct snd_pcm_hardware loopback_pcm_hardware =
 527 {
 528         .info =         (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_MMAP |
 529                          SNDRV_PCM_INFO_MMAP_VALID),
 530         .formats =      (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S16_BE |
 531                          SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_S32_BE |
 532                          SNDRV_PCM_FMTBIT_FLOAT_LE | SNDRV_PCM_FMTBIT_FLOAT_BE),
 533         .rates =        SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_192000,
 534         .rate_min =             8000,
 535         .rate_max =             192000,
 536         .channels_min =         1,
 537         .channels_max =         32,
 538         .buffer_bytes_max =     2 * 1024 * 1024,
 539         .period_bytes_min =     64,
 540         /* note check overflow in frac_pos() using pcm_rate_shift before
 541            changing period_bytes_max value */
 542         .period_bytes_max =     1024 * 1024,
 543         .periods_min =          1,
 544         .periods_max =          1024,
 545         .fifo_size =            0,
 546 };
 547
 548 static void loopback_runtime_free(struct snd_pcm_runtime *runtime)
 549 {
 550         struct loopback_pcm *dpcm = runtime->private_data;
 551         kfree(dpcm);
 552 }
 553
 554 static int loopback_hw_params(struct snd_pcm_substream *substream,
 555                               struct snd_pcm_hw_params *params)
 556 {
 557         return snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(params));
 558 }
 559
 560 static int loopback_hw_free(struct snd_pcm_substream *substream)
 561 {
 562         struct snd_pcm_runtime *runtime = substream->runtime;
 563         struct loopback_pcm *dpcm = runtime->private_data;
 564         struct loopback_cable *cable = dpcm->cable;
 565
 566         mutex_lock(&dpcm->loopback->cable_lock);
 567         cable->valid &= ~(1 << substream->stream);
 568         mutex_unlock(&dpcm->loopback->cable_lock);
 569         return snd_pcm_lib_free_pages(substream);
 570 }
 571
 572 static unsigned int get_cable_index(struct snd_pcm_substream *substream)
 573 {
 574         if (!substream->pcm->device)
 575                 return substream->stream;
 576         else
 577                 return !substream->stream;
 578 }
 579
 580 static int rule_format(struct snd_pcm_hw_params *params,
 581                        struct snd_pcm_hw_rule *rule)
 582 {
 583
 584         struct snd_pcm_hardware *hw = rule->private;
 585         struct snd_mask *maskp = hw_param_mask(params, rule->var);
 586
 587         maskp->bits[0] &= (u_int32_t)hw->formats;
 588         maskp->bits[1] &= (u_int32_t)(hw->formats >> 32);
 589         memset(maskp->bits + 2, 0, (SNDRV_MASK_MAX-64) / 8); /* clear rest */
 590         if (! maskp->bits[0] && ! maskp->bits[1])
 591                 return -EINVAL;
 592         return 0;
 593 }
 594
 595 static int rule_rate(struct snd_pcm_hw_params *params,
 596                      struct snd_pcm_hw_rule *rule)
 597 {
 598         struct snd_pcm_hardware *hw = rule->private;
 599         struct snd_interval t;
 600
 601         t.min = hw->rate_min;
 602         t.max = hw->rate_max;
 603         t.openmin = t.openmax = 0;
 604         t.integer = 0;
 605         return snd_interval_refine(hw_param_interval(params, rule->var), &t);
 606 }
 607
 608 static int rule_channels(struct snd_pcm_hw_params *params,
 609                          struct snd_pcm_hw_rule *rule)
 610 {
 611         struct snd_pcm_hardware *hw = rule->private;
 612         struct snd_interval t;
 613
 614         t.min = hw->channels_min;
 615         t.max = hw->channels_max;
 616         t.openmin = t.openmax = 0;
 617         t.integer = 0;
 618         return snd_interval_refine(hw_param_interval(params, rule->var), &t);
 619 }
 620
 621 static int loopback_open(struct snd_pcm_substream *substream)
 622 {
 623         struct snd_pcm_runtime *runtime = substream->runtime;
 624         struct loopback *loopback = substream->private_data;
 625         struct loopback_pcm *dpcm;
 626         struct loopback_cable *cable;
 627         int err = 0;
 628         int dev = get_cable_index(substream);
 629
 630         mutex_lock(&loopback->cable_lock);
 631         dpcm = kzalloc(sizeof(*dpcm), GFP_KERNEL);
 632         if (!dpcm) {
 633                 err = -ENOMEM;
 634                 goto unlock;
 635         }
 636         dpcm->loopback = loopback;
 637         dpcm->substream = substream;
 638         setup_timer(&dpcm->timer, loopback_timer_function,
 639                     (unsigned long)dpcm);
 640
 641         cable = loopback->cables[substream->number][dev];
 642         if (!cable) {
 643                 cable = kzalloc(sizeof(*cable), GFP_KERNEL);
 644                 if (!cable) {
 645                         kfree(dpcm);
 646                         err = -ENOMEM;
 647                         goto unlock;
 648                 }
 649                 spin_lock_init(&cable->lock);
 650                 cable->hw = loopback_pcm_hardware;
 651                 loopback->cables[substream->number][dev] = cable;
 652         }
 653         dpcm->cable = cable;
 654         cable->streams[substream->stream] = dpcm;
 655
 656         snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
 657
 658         /* use dynamic rules based on actual runtime->hw values */
 659         /* note that the default rules created in the PCM midlevel code */
 660         /* are cached -> they do not reflect the actual state */
 661         err = snd_pcm_hw_rule_add(runtime, 0,
 662                                   SNDRV_PCM_HW_PARAM_FORMAT,
 663                                   rule_format, &runtime->hw,
 664                                   SNDRV_PCM_HW_PARAM_FORMAT, -1);
 665         if (err < 0)
 666                 goto unlock;
 667         err = snd_pcm_hw_rule_add(runtime, 0,
 668                                   SNDRV_PCM_HW_PARAM_RATE,
 669                                   rule_rate, &runtime->hw,
 670                                   SNDRV_PCM_HW_PARAM_RATE, -1);
 671         if (err < 0)
 672                 goto unlock;
 673         err = snd_pcm_hw_rule_add(runtime, 0,
 674                                   SNDRV_PCM_HW_PARAM_CHANNELS,
 675                                   rule_channels, &runtime->hw,
 676                                   SNDRV_PCM_HW_PARAM_CHANNELS, -1);
 677         if (err < 0)
 678                 goto unlock;
 679
 680         runtime->private_data = dpcm;
 681         runtime->private_free = loopback_runtime_free;
 682         if (get_notify(dpcm))
 683                 runtime->hw = loopback_pcm_hardware;
 684         else
 685                 runtime->hw = cable->hw;
 686  unlock:
 687         mutex_unlock(&loopback->cable_lock);
 688         return err;
 689 }
 690
 691 static int loopback_close(struct snd_pcm_substream *substream)
 692 {
 693         struct loopback *loopback = substream->private_data;
 694         struct loopback_pcm *dpcm = substream->runtime->private_data;
 695         struct loopback_cable *cable;
 696         int dev = get_cable_index(substream);
 697
 698         loopback_timer_stop(dpcm);
 699         mutex_lock(&loopback->cable_lock);
 700         cable = loopback->cables[substream->number][dev];
 701         if (cable->streams[!substream->stream]) {
 702                 /* other stream is still alive */
 703                 cable->streams[substream->stream] = NULL;
 704         } else {
 705                 /* free the cable */
 706                 loopback->cables[substream->number][dev] = NULL;
 707                 kfree(cable);
 708         }
 709         mutex_unlock(&loopback->cable_lock);
 710         return 0;
 711 }
 712
 713 static struct snd_pcm_ops loopback_playback_ops = {
 714         .open =         loopback_open,
 715         .close =        loopback_close,
 716         .ioctl =        snd_pcm_lib_ioctl,
 717         .hw_params =    loopback_hw_params,
 718         .hw_free =      loopback_hw_free,
 719         .prepare =      loopback_prepare,
 720         .trigger =      loopback_trigger,
 721         .pointer =      loopback_pointer,
 722 };
 723
 724 static struct snd_pcm_ops loopback_capture_ops = {
 725         .open =         loopback_open,
 726         .close =        loopback_close,
 727         .ioctl =        snd_pcm_lib_ioctl,
 728         .hw_params =    loopback_hw_params,
 729         .hw_free =      loopback_hw_free,
 730         .prepare =      loopback_prepare,
 731         .trigger =      loopback_trigger,
 732         .pointer =      loopback_pointer,
 733 };
 734
 735 static int __devinit loopback_pcm_new(struct loopback *loopback,
 736                                       int device, int substreams)
 737 {
 738         struct snd_pcm *pcm;
 739         int err;
 740
 741         err = snd_pcm_new(loopback->card, "Loopback PCM", device,
 742                           substreams, substreams, &pcm);
 743         if (err < 0)
 744                 return err;
 745         snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &loopback_playback_ops);
 746         snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &loopback_capture_ops);
 747
 748         pcm->private_data = loopback;
 749         pcm->info_flags = 0;
 750         strcpy(pcm->name, "Loopback PCM");
 751
 752         loopback->pcm[device] = pcm;
 753
 754         snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
 755                         snd_dma_continuous_data(GFP_KERNEL),
 756                         0, 2 * 1024 * 1024);
 757         return 0;
 758 }
 759
 760 static int loopback_rate_shift_info(struct snd_kcontrol *kcontrol,
 761                                     struct snd_ctl_elem_info *uinfo)
 762 {
 763         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 764         uinfo->count = 1;
 765         uinfo->value.integer.min = 80000;
 766         uinfo->value.integer.max = 120000;
 767         uinfo->value.integer.step = 1;
 768         return 0;
 769 }
 770
 771 static int loopback_rate_shift_get(struct snd_kcontrol *kcontrol,
 772                                    struct snd_ctl_elem_value *ucontrol)
 773 {
 774         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 775
 776         ucontrol->value.integer.value[0] =
 777                 loopback->setup[kcontrol->id.subdevice]
 778                                [kcontrol->id.device].rate_shift;
 779         return 0;
 780 }
 781
 782 static int loopback_rate_shift_put(struct snd_kcontrol *kcontrol,
 783                                    struct snd_ctl_elem_value *ucontrol)
 784 {
 785         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 786         unsigned int val;
 787         int change = 0;
 788
 789         val = ucontrol->value.integer.value[0];
 790         if (val < 80000)
 791                 val = 80000;
 792         if (val > 120000)
 793                 val = 120000;
 794         mutex_lock(&loopback->cable_lock);
 795         if (val != loopback->setup[kcontrol->id.subdevice]
 796                                   [kcontrol->id.device].rate_shift) {
 797                 loopback->setup[kcontrol->id.subdevice]
 798                                [kcontrol->id.device].rate_shift = val;
 799                 change = 1;
 800         }
 801         mutex_unlock(&loopback->cable_lock);
 802         return change;
 803 }
 804
 805 static int loopback_notify_get(struct snd_kcontrol *kcontrol,
 806                                struct snd_ctl_elem_value *ucontrol)
 807 {
 808         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 809
 810         ucontrol->value.integer.value[0] =
 811                 loopback->setup[kcontrol->id.subdevice]
 812                                [kcontrol->id.device].notify;
 813         return 0;
 814 }
 815
 816 static int loopback_notify_put(struct snd_kcontrol *kcontrol,
 817                                struct snd_ctl_elem_value *ucontrol)
 818 {
 819         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 820         unsigned int val;
 821         int change = 0;
 822
 823         val = ucontrol->value.integer.value[0] ? 1 : 0;
 824         if (val != loopback->setup[kcontrol->id.subdevice]
 825                                 [kcontrol->id.device].notify) {
 826                 loopback->setup[kcontrol->id.subdevice]
 827                         [kcontrol->id.device].notify = val;
 828                 change = 1;
 829         }
 830         return change;
 831 }
 832
 833 static int loopback_active_get(struct snd_kcontrol *kcontrol,
 834                                struct snd_ctl_elem_value *ucontrol)
 835 {
 836         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 837         struct loopback_cable *cable = loopback->cables
 838                         [kcontrol->id.subdevice][kcontrol->id.device ^ 1];
 839         unsigned int val = 0;
 840
 841         if (cable != NULL)
 842                 val = (cable->running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) ?
 843                                                                         1 : 0;
 844         ucontrol->value.integer.value[0] = val;
 845         return 0;
 846 }
 847
 848 static int loopback_format_info(struct snd_kcontrol *kcontrol,
 849                                 struct snd_ctl_elem_info *uinfo)
 850 {
 851         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 852         uinfo->count = 1;
 853         uinfo->value.integer.min = 0;
 854         uinfo->value.integer.max = SNDRV_PCM_FORMAT_LAST;
 855         uinfo->value.integer.step = 1;
 856         return 0;
 857 }
 858
 859 static int loopback_format_get(struct snd_kcontrol *kcontrol,
 860                                struct snd_ctl_elem_value *ucontrol)
 861 {
 862         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 863
 864         ucontrol->value.integer.value[0] =
 865                 loopback->setup[kcontrol->id.subdevice]
 866                                [kcontrol->id.device].format;
 867         return 0;
 868 }
 869
 870 static int loopback_rate_info(struct snd_kcontrol *kcontrol,
 871                               struct snd_ctl_elem_info *uinfo)
 872 {
 873         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 874         uinfo->count = 1;
 875         uinfo->value.integer.min = 0;
 876         uinfo->value.integer.max = 192000;
 877         uinfo->value.integer.step = 1;
 878         return 0;
 879 }
 880
 881 static int loopback_rate_get(struct snd_kcontrol *kcontrol,
 882                              struct snd_ctl_elem_value *ucontrol)
 883 {
 884         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 885
 886         ucontrol->value.integer.value[0] =
 887                 loopback->setup[kcontrol->id.subdevice]
 888                                [kcontrol->id.device].rate;
 889         return 0;
 890 }
 891
 892 static int loopback_channels_info(struct snd_kcontrol *kcontrol,
 893                                   struct snd_ctl_elem_info *uinfo)
 894 {
 895         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 896         uinfo->count = 1;
 897         uinfo->value.integer.min = 1;
 898         uinfo->value.integer.max = 1024;
 899         uinfo->value.integer.step = 1;
 900         return 0;
 901 }
 902
 903 static int loopback_channels_get(struct snd_kcontrol *kcontrol,
 904                                  struct snd_ctl_elem_value *ucontrol)
 905 {
 906         struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 907
 908         ucontrol->value.integer.value[0] =
 909                 loopback->setup[kcontrol->id.subdevice]
 910                                [kcontrol->id.device].channels;
 911         return 0;
 912 }
 913
 914 static struct snd_kcontrol_new loopback_controls[]  __devinitdata = {
 915 {
 916         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 917         .name =         "PCM Rate Shift 100000",
 918         .info =         loopback_rate_shift_info,
 919         .get =          loopback_rate_shift_get,
 920         .put =          loopback_rate_shift_put,
 921 },
 922 {
 923         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 924         .name =         "PCM Notify",
 925         .info =         snd_ctl_boolean_mono_info,
 926         .get =          loopback_notify_get,
 927         .put =          loopback_notify_put,
 928 },
 929 #define ACTIVE_IDX 2
 930 {
 931         .access =       SNDRV_CTL_ELEM_ACCESS_READ,
 932         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 933         .name =         "PCM Slave Active",
 934         .info =         snd_ctl_boolean_mono_info,
 935         .get =          loopback_active_get,
 936 },
 937 #define FORMAT_IDX 3
 938 {
 939         .access =       SNDRV_CTL_ELEM_ACCESS_READ,
 940         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 941         .name =         "PCM Slave Format",
 942         .info =         loopback_format_info,
 943         .get =          loopback_format_get
 944 },
 945 #define RATE_IDX 4
 946 {
 947         .access =       SNDRV_CTL_ELEM_ACCESS_READ,
 948         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 949         .name =         "PCM Slave Rate",
 950         .info =         loopback_rate_info,
 951         .get =          loopback_rate_get
 952 },
 953 #define CHANNELS_IDX 5
 954 {
 955         .access =       SNDRV_CTL_ELEM_ACCESS_READ,
 956         .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 957         .name =         "PCM Slave Channels",
 958         .info =         loopback_channels_info,
 959         .get =          loopback_channels_get
 960 }
 961 };
 962
 963 static int __devinit loopback_mixer_new(struct loopback *loopback, int notify)
 964 {
 965         struct snd_card *card = loopback->card;
 966         struct snd_pcm *pcm;
 967         struct snd_kcontrol *kctl;
 968         struct loopback_setup *setup;
 969         int err, dev, substr, substr_count, idx;
 970
 971         strcpy(card->mixername, "Loopback Mixer");
 972         for (dev = 0; dev < 2; dev++) {
 973                 pcm = loopback->pcm[dev];
 974                 substr_count =
 975                     pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count;
 976                 for (substr = 0; substr < substr_count; substr++) {
 977                         setup = &loopback->setup[substr][dev];
 978                         setup->notify = notify;
 979                         setup->rate_shift = NO_PITCH;
 980                         setup->format = SNDRV_PCM_FORMAT_S16_LE;
 981                         setup->rate = 48000;
 982                         setup->channels = 2;
 983                         for (idx = 0; idx < ARRAY_SIZE(loopback_controls);
 984                                                                         idx++) {
 985                                 kctl = snd_ctl_new1(&loopback_controls[idx],
 986                                                     loopback);
 987                                 if (!kctl)
 988                                         return -ENOMEM;
 989                                 kctl->id.device = dev;
 990                                 kctl->id.subdevice = substr;
 991                                 switch (idx) {
 992                                 case ACTIVE_IDX:
 993                                         setup->active_id = kctl->id;
 994                                         break;
 995                                 case FORMAT_IDX:
 996                                         setup->format_id = kctl->id;
 997                                         break;
 998                                 case RATE_IDX:
 999                                         setup->rate_id = kctl->id;
1000                                         break;
1001                                 case CHANNELS_IDX:
1002                                         setup->channels_id = kctl->id;
1003                                         break;
1004                                 default:
1005                                         break;
1006                                 }
1007                                 err = snd_ctl_add(card, kctl);
1008                                 if (err < 0)
1009                                         return err;
1010                         }
1011                 }
1012         }
1013         return 0;
1014 }
1015
1016 #ifdef CONFIG_PROC_FS
1017
1018 static void print_dpcm_info(struct snd_info_buffer *buffer,
1019                             struct loopback_pcm *dpcm,
1020                             const char *id)
1021 {
1022         snd_iprintf(buffer, "  %s\n", id);
1023         if (dpcm == NULL) {
1024                 snd_iprintf(buffer, "    inactive\n");
1025                 return;
1026         }
1027         snd_iprintf(buffer, "    buffer_size:\t%u\n", dpcm->pcm_buffer_size);
1028         snd_iprintf(buffer, "    buffer_pos:\t\t%u\n", dpcm->buf_pos);
1029         snd_iprintf(buffer, "    silent_size:\t%u\n", dpcm->silent_size);
1030         snd_iprintf(buffer, "    period_size:\t%u\n", dpcm->pcm_period_size);
1031         snd_iprintf(buffer, "    bytes_per_sec:\t%u\n", dpcm->pcm_bps);
1032         snd_iprintf(buffer, "    sample_align:\t%u\n", dpcm->pcm_salign);
1033         snd_iprintf(buffer, "    rate_shift:\t\t%u\n", dpcm->pcm_rate_shift);
1034         snd_iprintf(buffer, "    update_pending:\t%u\n",
1035                                                 dpcm->period_update_pending);
1036         snd_iprintf(buffer, "    irq_pos:\t\t%u\n", dpcm->irq_pos);
1037         snd_iprintf(buffer, "    period_frac:\t%u\n", dpcm->period_size_frac);
1038         snd_iprintf(buffer, "    last_jiffies:\t%lu (%lu)\n",
1039                                         dpcm->last_jiffies, jiffies);
1040         snd_iprintf(buffer, "    timer_expires:\t%lu\n", dpcm->timer.expires);
1041 }
1042
1043 static void print_substream_info(struct snd_info_buffer *buffer,
1044                                  struct loopback *loopback,
1045                                  int sub,
1046                                  int num)
1047 {
1048         struct loopback_cable *cable = loopback->cables[sub][num];
1049
1050         snd_iprintf(buffer, "Cable %i substream %i:\n", num, sub);
1051         if (cable == NULL) {
1052                 snd_iprintf(buffer, "  inactive\n");
1053                 return;
1054         }
1055         snd_iprintf(buffer, "  valid: %u\n", cable->valid);
1056         snd_iprintf(buffer, "  running: %u\n", cable->running);
1057         print_dpcm_info(buffer, cable->streams[0], "Playback");
1058         print_dpcm_info(buffer, cable->streams[1], "Capture");
1059 }
1060
1061 static void print_cable_info(struct snd_info_entry *entry,
1062                              struct snd_info_buffer *buffer)
1063 {
1064         struct loopback *loopback = entry->private_data;
1065         int sub, num;
1066
1067         mutex_lock(&loopback->cable_lock);
1068         num = entry->name[strlen(entry->name)-1];
1069         num = num == '0' ? 0 : 1;
1070         for (sub = 0; sub < MAX_PCM_SUBSTREAMS; sub++)
1071                 print_substream_info(buffer, loopback, sub, num);
1072         mutex_unlock(&loopback->cable_lock);
1073 }
1074
1075 static int __devinit loopback_proc_new(struct loopback *loopback, int cidx)
1076 {
1077         char name[32];
1078         struct snd_info_entry *entry;
1079         int err;
1080
1081         snprintf(name, sizeof(name), "cable#%d", cidx);
1082         err = snd_card_proc_new(loopback->card, name, &entry);
1083         if (err < 0)
1084                 return err;
1085
1086         snd_info_set_text_ops(entry, loopback, print_cable_info);
1087         return 0;
1088 }
1089
1090 #else /* !CONFIG_PROC_FS */
1091
1092 #define loopback_proc_new(loopback, cidx) do { } while (0)
1093
1094 #endif
1095
1096 static int __devinit loopback_probe(struct platform_device *devptr)
1097 {
1098         struct snd_card *card;
1099         struct loopback *loopback;
1100         int dev = devptr->id;
1101         int err;
1102
1103         err = snd_card_create(index[dev], id[dev], THIS_MODULE,
1104                               sizeof(struct loopback), &card);
1105         if (err < 0)
1106                 return err;
1107         loopback = card->private_data;
1108
1109         if (pcm_substreams[dev] < 1)
1110                 pcm_substreams[dev] = 1;
1111         if (pcm_substreams[dev] > MAX_PCM_SUBSTREAMS)
1112                 pcm_substreams[dev] = MAX_PCM_SUBSTREAMS;
1113
1114         loopback->card = card;
1115         mutex_init(&loopback->cable_lock);
1116
1117         err = loopback_pcm_new(loopback, 0, pcm_substreams[dev]);
1118         if (err < 0)
1119                 goto __nodev;
1120         err = loopback_pcm_new(loopback, 1, pcm_substreams[dev]);
1121         if (err < 0)
1122                 goto __nodev;
1123         err = loopback_mixer_new(loopback, pcm_notify[dev] ? 1 : 0);
1124         if (err < 0)
1125                 goto __nodev;
1126         loopback_proc_new(loopback, 0);
1127         loopback_proc_new(loopback, 1);
1128         strcpy(card->driver, "Loopback");
1129         strcpy(card->shortname, "Loopback");
1130         sprintf(card->longname, "Loopback %i", dev + 1);
1131         err = snd_card_register(card);
1132         if (!err) {
1133                 platform_set_drvdata(devptr, card);
1134                 return 0;
1135         }
1136       __nodev:
1137         snd_card_free(card);
1138         return err;
1139 }
1140
1141 static int __devexit loopback_remove(struct platform_device *devptr)
1142 {
1143         snd_card_free(platform_get_drvdata(devptr));
1144         platform_set_drvdata(devptr, NULL);
1145         return 0;
1146 }
1147
1148 #ifdef CONFIG_PM
1149 static int loopback_suspend(struct platform_device *pdev,
1150                                 pm_message_t state)
1151 {
1152         struct snd_card *card = platform_get_drvdata(pdev);
1153         struct loopback *loopback = card->private_data;
1154
1155         snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
1156
1157         snd_pcm_suspend_all(loopback->pcm[0]);
1158         snd_pcm_suspend_all(loopback->pcm[1]);
1159         return 0;
1160 }
1161
1162 static int loopback_resume(struct platform_device *pdev)
1163 {
1164         struct snd_card *card = platform_get_drvdata(pdev);
1165
1166         snd_power_change_state(card, SNDRV_CTL_POWER_D0);
1167         return 0;
1168 }
1169 #endif
1170
1171 #define SND_LOOPBACK_DRIVER     "snd_aloop"
1172
1173 static struct platform_driver loopback_driver = {
1174         .probe          = loopback_probe,
1175         .remove         = __devexit_p(loopback_remove),
1176 #ifdef CONFIG_PM
1177         .suspend        = loopback_suspend,
1178         .resume         = loopback_resume,
1179 #endif
1180         .driver         = {
1181                 .name   = SND_LOOPBACK_DRIVER
1182         },
1183 };
1184
1185 static void loopback_unregister_all(void)
1186 {
1187         int i;
1188
1189         for (i = 0; i < ARRAY_SIZE(devices); ++i)
1190                 platform_device_unregister(devices[i]);
1191         platform_driver_unregister(&loopback_driver);
1192 }
1193
1194 static int __init alsa_card_loopback_init(void)
1195 {
1196         int i, err, cards;
1197
1198         err = platform_driver_register(&loopback_driver);
1199         if (err < 0)
1200                 return err;
1201
1202
1203         cards = 0;
1204         for (i = 0; i < SNDRV_CARDS; i++) {
1205                 struct platform_device *device;
1206                 if (!enable[i])
1207                         continue;
1208                 device = platform_device_register_simple(SND_LOOPBACK_DRIVER,
1209                                                          i, NULL, 0);
1210                 if (IS_ERR(device))
1211                         continue;
1212                 if (!platform_get_drvdata(device)) {
1213                         platform_device_unregister(device);
1214                         continue;
1215                 }
1216                 devices[i] = device;
1217                 cards++;
1218         }
1219         if (!cards) {
1220 #ifdef MODULE
1221                 printk(KERN_ERR "aloop: No loopback enabled\n");
1222 #endif
1223                 loopback_unregister_all();
1224                 return -ENODEV;
1225         }
1226         return 0;
1227 }
1228
1229 static void __exit alsa_card_loopback_exit(void)
1230 {
1231         loopback_unregister_all();
1232 }
1233
1234 module_init(alsa_card_loopback_init)
1235 module_exit(alsa_card_loopback_exit)